1DII, C.Fn 17, field sports

Those of you using 1D type body for shooting field sports, especially with long lenses greater than 200mm, what do you set your C.Fn 17 to? Do you use expansion? I know SI recommends to set it to 1, but I wanted to see what your experience is with using AF expansion.

TIA

Personally I have set it to 0. I tried once loooong time ago (still on Eos 1v) and I hated result. Focus was all over place, so I decided camera is more stupid then I am, so I went back to 0. With Cfn17 set to 0, I, as photographer, decide where focus will be, not that camera decided if focus is on front player, or on player next to him. Focus should be there, where you want it, not where camera wants it. I don't care about SI recommendations, so I have it set my way... afterall I have few experiences after shooting pro sport for living for years and years

For field sports where I can't fill the frame with my subject, I set mine to 1. For basketball and other times when I can fill the frame, I set it to 0.

I'm not sure what mine is currently on but I'll have to have a look later.